1. Field of Invention
This invention relates to an oscillator used in self-propelled submersible suction cleaners, particularly swimming pool suction cleaners. The term "self-propelled" herein means that the suction cleaner is not manually propelled but includes means operated by the flow of water through the suction head to cause propulsion of the device.
2. Description of Background Art
The most common form of propulsion mechanism comprises an oscillator disposed within the flow path through the suction head of the cleaner, which flow is caused by coupling of the suction head to a filter pump for the pool by suitable hose means. The oscillator is so shaped that flow therepast causes it to move to and fro on its pivot, the oscillator engaging the housing of the suction head at the extremity of its pivotal movement on each side, the impact causing the head to advance stepwise along a surface to be swept.
In order for the oscillator to operate efficiently it must be located in a suction chamber so that the oscillator pivots in close proximity to a wall of the chamber. This is necessary so that the bulk of flow past the oscillator moves along surfaces designed to provide the to and fro movement of the oscillator.
If flow is dissipated around the oscillator along non-functional surfaces the operation of the oscillator become inefficient and the advance motion of the suction head sluggish. The oscillator can, of course, fit neatly into the suction chamber of the head to provide for efficient action thereof but a swimming pool floor often has grit particles which are drawn into the suction cleaner and such grit is liable to lodge between the oscillator and the closely spaced chamber wall causing the oscillator to lose efficiency through friction or even to stick.